Its good they are not facing the law. This kind of justice provides for a lasting impression and behaviour modification.
If arrested, it only provides the Cops to take a bribe from him and let him go.
Both are forms of punishment, one in which you are humiliated, other in which you are blackmailed into giving money and encouraging corruption at the same time.
The First option is ALWAYS the better option and that is what happened. FAR better than calling Cops.
It actually served Long Term Justice. He and his family will now think twice about showing disrespect to the Nation. they have learnt to respect others, because others have considered him part of their society and have insisted he act appropriately. Sending him to jail would only turn him into a criminal and his resentment will only increase.
Do you really think you can find cops inside a Mall in Mumbai ?
Even if you go and call them and tell them that a man is not standing up for the Anthem, they will ask you to slap him a few times an let him go ;lol: ..... that is if they don't laught at you first.
Meanwhile the movie would have started and you would have missed half of it for no faults of yours.
End of the day don't pledge your common sense to "logic".